Final answer:
Dada is the art movement that most directly sought to challenge and redefine the traditional concept of art through its radical practices and anti-establishment sentiments. The correct option is D.
Step-by-step explanation:
The art movement that was most clearly dedicated to breaking the traditional definition of art is Dada. This movement emerged amid the turmoil of World War I and aimed to protest against the conventional standards and established norms of art.
Dada artists utilized a variety of non-traditional media, including collage, photomontage, and assemblage, and they were known for denouncing art's status quo and the capitalist system which they perceived as an underlying cause of the war.
Surrealism and Futurism were also influential movements that pursued innovative artistic expressions, but Dada's radical approach fundamentally challenged and reshaped the contemporary concept of what art could be.